I did a froogle search on e6600 and found a few hits for about $350-$360. Are these all OEM's? Do you think the retail price may drop a bit in the next 4-6 weeks?
Not sure if they are OEMs, but I wouldn't be surprised if some were.
As for price drops, I can only hope so. With the high demand and constant complaints of availablity, etailers have that "greed" bug in their ears, and price markups were rampant early. Newegg even stopped smoking crack enough to lower their prices to a more "reasonable" price for retail chips. At $699 and $499 for E6700/E6600 listed (out of stock, of course) at the Egg, it's still a little high, but it is a retail box version.
In 4-6 weeks, prices might stablize, but I won't guarantee a huge drop.